Document EP 0 528 781 discloses protective fire-resistant glazing comprising a glazed element housed in a fixing frame with a prestressed silicate glass pane bonded on top on the fire side, which pane ends a certain distance away from the fixing frame. Arranged on the fixing frame are protruding individual fixing leaves for supporting the additional silicate glass pane and pressing elastically against its main surface. In the event of a fire, the additional pane is supposed to ensure uniform heating and play a part in absorbing the heat energy so that the glazed element behind it resists the fire for longer. To bond the additional pane on, use may be made, for example, of polyvinyl butyral or of some other appropriate organic synthetic material. Under the effect of the heat, the adhesive layer melts, which means that the bond no longer holds. The additional pane is then held in its position only mechanically by the fixing leaves. Because the fixing leaves are mounted at isolated points, there remains no other widespread screen protecting the additional pane, which is therefore heated more or less uniformly, which means that no dangerous temperature differences occur within the glass nor, in consequence, do any dangerous tensions appear therein.
One disadvantage of the fire-resistant glazing described in that publication, with its fixing and with its protection against falling out, lies in the fact that use is made of a frame and of fixing leaves which detract from the visual appearance and make the tasks of cleaning more complicated. The surface of the glazing is also fissured by the seals of the set-back additional pane.
There is a need for an improved fixing for composite glazing used, as a preference, in glazing that affords protection against fire, or fire-resistant glazing.